輸入一個字符串，輸出時數字倒序。例如：輸入"hello2345wo7654",輸出則為"hello5432wo4567"

public class ReserveString {
    public static void main(String[] args) {
        System.out.println("Please Input String:");
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        boolean state = false;
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < a.length(); i++) {
            String str = a.substring(i, i + 1);
            if (str.matches("^[0-9]*$")) {
                state = true;
                sb.append(str);
            } else {
                if (state) {
                    System.out.print(sb.reverse().toString());
                    state = false;
                    sb.setLength(0);
                }
                System.out.print(str);
            }
        }
        if (state) {
            System.out.print(sb.reverse().toString());
        }

    }
}